Method of casting hollow metal bodies.



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N. .I M A J N E B l m METHOD OF CASTING HOLLOW METAL BODIES. I

APPLICATION FILED JUNE 6, 1907.

INVENTOR y f FIGS.

wnNEssEs: @Ma/MWA GEORGE HILLARD BENJAMIN, OF NEW YORK, N. Y., SSIGNOR TO THE COE BRASS MANU- FACTURING COMPANY, A CORPORATION QF CONNECTIC'Twwv H.

METOD OF CASTING HOLLOW METAAL BODIES.

ivo. 895,535;

Patented Aug. 1v1, 190B.

Application led. June 6, 1907. Serial No..377,615.

To all whom 'it may concern:

Vsupporting frame; 6 casting c linder.

Be it known that I, GEORGE HILLARD BEXJAMIN, a citizen of the United States, residing at the city, county, and State of New York, have invented a Method of Casting Hollow Metal Bodies, of which the following is' a specification. i

Mv invention relates to a method of casting hollow metal lio'dies, especiall such as are formed of a metal or alloy whic is freely oxidizable, when 'at the casting temperature.

Steel and iron have-heretofore been cast in a horizontally rotatable mold, and this has been possible, owing to the fact that such metals are not freely oxidizable when at the casting temperature.

Broadly stated, my invention consists in casting the molt-en material of which the hollow metal body is to be formed into a reducing atmosphere, and while therein subjecting it to the action of centrifugal force.

The accompanying drawings will serve to illustrate one form which the apparatus, employed in carrying out the invention, may take, in which Figure 1 is a longitudinal section, with the parts iii the casting position; Fig. 2 is a simiar-view with the parts in the position for removing the hollow casting; and Fig. 3 is a vertical transverse section on the line X -X of Fig. 1, looking to the left.

Referring to the drawing: 5 indicates a This cylinder is supported upon earings 7, so as to enable it to be swung from the position shown in Fig. 1 to that shown in Fig. 2.

S indicates a hopper, through Which the molten metal is fed into the cylinder 6.

9 indicates la-tank, containing a reducing gas, which is connected by a pipe 10 to the interior of the hopper 8 and by a pipe 11 to the interior of the cylinder 6. These pipes are provided with suitable valves 12, 13.

It is essential in an apparatus of the characier described that the c linder have its axis of rotation maintaine horizontal and that the rotation be uniform. The cylinder (ima be rotated in any suitable manner, as by a g elt, sprocket gear, worm gear, or otherwise.

In the present drawings, I have shown the rotating means as consisting of a'polvphase electric motor 14, the rotor member o which 15 is mounted upon the exterior of the cylinelectrically and as to heat.

. i 'UNITED STATES ieiirnNT oFFicE.

der 6 and suitably 'insulatedy therefrom both 55 Obviously, after a casting is formed within i the cylinder 6, it is necessary to remove it. Many plans may be adopted, which will at once suggest themselves to engineers. 'One convenient way is, as shown in the-figures, i. e.,-to mount the motor 14 and cylinder 6 upon bearings 7, so that the cylinder may be swung in the arc of a circle, and mount the cooperating ends 16,I 17, which act as c losures for the ends of the cylinder, upon sliding bearings 18, 19. These bearings are cennected through a handle 2O and cooperating lever arms 21, 22 and 23,50 that simu taneous movement toward or from each other may be given the bearings and ends.

The apparatus above described, as before stated, is such as may be lused. Of course, other apparatus ma be used.-

The method emp oyed consists in relmiinai-ily charging the interior of the cy inder 6 and the hopper 8 with a reducing gas, such,

for instance, as carbon oxid or h drogen under ressure. I prefer that t ie pressure sliou d be double that of the atmosphere, i. e.,-30 pounds to the square inch. After the cylinder and hopper are charged with gas the c flinder is rotated. In practice, I have foun that the speed of rotation of the cylinthe pressure of the gas in the hopper and the cylinder being maintained. The metal flows from the hopper into the cylinder and by `centrifugal force is distributed to the inner side of the cylinder, distributing itself uni' ormly over the entire interior of the cylinder. The pouring is continued until aliollow body has been formed of the required thickness.

During the entire pourincr, and'or some minutes after the pouring as ceased, the ressure of the reducing gas vwithin the cyliner is maintained. The reducing gas within the cylinder acts firstly to remove the air from the interior of the cylinder; secondly,

ai 'i 35 tion o y K to prevent access of air to the interior of the cylinder thirdly, t'o efect a chemical combination with any occluded air carried by the heated metal or allov, and fcurthly, to reduce F'6' any oxid which may be formed on the meta-l or alloy inthe melting operation or during pourino'.

`I hazye found in some cases that order to Obtain the best results,- it is preferable to combine two reducing gases, as, for instance,

hydrogen and carbon.

As soon as the casting is completed and the metal suiciently cooled, the gas is shut off and the rotation of the cylinder stopped and the cylinder tilted to the position shown in 2. Contraction of the casting permits 1t to be readily slid or pulled out of the cylinder.

In practice I have cast hollow -ingots from copper, brass, various alloys, zinc, iron and `stee ,in all cases obtainin a hollow ingot -with solidwalls, free from low holes or occluded air, and which are in condition to be subsequently treated by rolling, drawing,

25. etc., as is usual in the manipulation of suc`h bodies.

The essential feature of novelty is, as before stated, the casting of the hot metal into a non-'oxidizing atmosphere and while 'in such atmosphere subjecting it to centrifugal action to cause metal to assume the shape of a hollow body.

AIt will be evident to engineers, that the same principle may be applied in the formadisks, bodies plaln on the interior but having angular surfaces, as for instance, hexagon or Octagon tubes, and the like.

Having thus described my invention, vI

40 claim:

1. The herein described method of formfing hollow metal bodies which comprises the provision of and the maintaining of a reducing atmosphere within a rotating mold, feedinnr the molten material of which the body is to -e formed into said mold, and while therein subjecting it to the action of centrifugal orce.

- 2. The herein described method of formi ing hollow metal bodies which consists in feeding the molten material of 'which the bodyT is to be formed, into e. hollow mold containing a reducing gas under pressure, and' while therein subjecting it to:` the action' of centrifugal force.

3.' The herein deseribed'mthod of forming hollow metal bodies which consists in feeding the moltemmaterial of which the' other shapes than tubes, for instance,

body is tobe formed, into a tubular rotating mold containing a reducing gas under prepssure.

4. The herein described method of forming hollow metal bodies which consists in whi e thereln subjecting it to the action of said reducin atmosphere and to the action of centrifuga force.

6. The herein described method of .forming hollow metal bodies which com rises the provision of and the maintaining opa redu'c- 1n atmosphere-within a hollow horizonta ydisposed tubular mold rotated at a high speed, feeding the molten material of which the body is to be formed into said mold, and subect' D' said material while in said mold to the action of said reducing atpiosphere and to the action of centrifugal orce.

7. The herein described method of'form ing hollow metal bodies` which comprises melting to a fluid condition the material of which the body is tobe formed, the provision.

ofl and the maintaining of a reducing atmosphere within a hollow tube rotated at'a high speed, feeding said material graduallyinto said hollow tube, and while therein subjectin atmosphere and to the action of centrifuga force. f

l8. The herein described method of forming hollow metal bodies .which com risesthe maintained exclusion of atmos reric air from within a hollow tube rotate at a high speed melting to a fluid condition the material of which the body is to be formed, feedin said material gradually into said hollow tu e while continuousl excluding the atmospheric air from the interior thereof:

In testimony whereof, I aflix my signature, in the presence of two witnesses.

Witnesses:

FREDERICK A. BLouN'r, AUGUSTA E. Mum.

GEORGE HILLARD BENJAMIN.

Ying said material to the action of said reduc- 

